...and on Tue, Jul 20, 2004 at 09:52:56AM +0200, [EMAIL PROTECTED] used the keyboard: > Hi all, > > I've been searching the list for a while but couldn't find any up-to-date > information relating to my problem. > We have a production server with postgresql on cygwin that currently deels > with about 200 Gigs of data (1 big IDE drive). We plan to move to linux > for some reasons I don't have to explain. > Our aim is also to be able to increase our storage capacity up to > approximately 1 or 2 terabytes and to speed up our production process. As > we are a small "microsoft addicted" company , we have some difficulties to > choose the best configuration that would best meet our needs. > Our production process is based on transaction (mostly huge inserts) and > disk access is the main bottlle-neck. > > Our main concern is hardware related : > > Would NAS or SAN be good solutions ? (I've read that NAS uses NFS which > could slow down the transfer rate ??) > Has anyone ever tried one of these with postgresql ? > > I would appreciate any comments. > Thanks in advance.
Hello Simon, We're testing 3ware Escalade 9000, which is a hardware-raid SATA controller with VERY good support for Linux (including direct access for S.M.A.R.T. applications, which is a serious problem with other RAID controllers), featuring RAID levels 0, 1, 10, 5, JBOD, up to 12 SATA channels (that's 3ware Escalade 9500S-12, they also come in 4- and 8-channel versions, up to four cards can be fitted into a system), up to 1GB battery-backed ECC RAM (128MB out-of-the-box) and most of all, excellent tuning guides that actually manage to exceed the scope of merely making you come up with good benchmark results for that controller in a specific test environment. Our preliminary tests show that a setup of four 250GB SATA Maxtors that aren't really qualified as fast drives, in RAID5 can deliver block writes of 50MB/s, rewrites at about 35MB/s and reads of approximately 180MB/s, which is rougly 2.5-times the performance of previous Escalades. You can find more info on Escalade 9000 series, benchmarks and other stuff here: http://www.3ware.com/products/serial_ata9000.asp http://www.3ware.com/products/benchmarks_sata.asp http://www.3ware.dk/fileadmin/3ware/documents/Benchmarks/Linux_kernel_2.6_Benchmarking.pdf Oh, and not to forget - the price for a 3ware 9500S-12, the version we're testing ranges between EUR1000 and EUR1500, depending on the contract you have with the reseller and the intended use of the device. SATA disks are dirt-cheap nowadays, as has been mentioned before. I do agree on the reliability of cache-usage setting those drives report though, it may or may not be true. But one never knows that for sure with SCSI drives either. At least you can assert that proper controller cache sizing with drives that usually feature 8MB (!!!) cache, will mostly ensure that even the largest amount of data that could fit into a hard disk cache of the entire array (96MB) will still be available in the controller cache after a power failure, for it to be re-checked and ensured it is properly written. Hope this helps, -- Grega Bremec Senior Administrator Noviforum Ltd., Software & Media http://www.noviforum.si/
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